External Reference (MAX4072)

The MAX4072 contains REFIN pin for external refer-

ence voltage. The allowable voltage range on REFIN is

≥ 5.1V.

Reference Output

(MAX4069/MAX4060/MAX4071)

The REFOUT of the MAX4069/MAX4070/MAX4071 can

sink 100µA and source 500µA. Keep the total capaci-

tance on REFOUT under 500pF to maintain stability.

Recommended Component Values

Ideally, the maximum load current develops the full-

scale sense voltage across the current-sense resistor.

Choose the gain needed to yield the maximum output

voltage required for the application:

gain of the device.

In applications monitoring high current, ensure that

tor’s power dissipation is exceeded, its value may drift

or it may fail altogether, causing a differential voltage

across the terminals in excess of the absolute maxi-

mum ratings. Use resistors specified for current- sens-

ing applications.

The MAX4069–MAX4072 sense a wide variety of cur-

rents with different sense-resistor values. Table 1 lists

common resistor values for typical operation of these

devices. Listed output voltage is with respect to REF.

source voltage to degrade through IR loss. For minimal

to be measured more accurately. This is because off-

sets become less significant when the sense voltage is

approximately 75mV (gain of 50V/V) or 50mV (gain of

100V/V) of sense voltage for the full-scale current in

each application.

Efficiency and Power Dissipation: At high-current lev-

this into consideration when choosing the resistor value

and its power dissipation (wattage) rating. Also, the

sense resistor’s value might drift if it is allowed to heat

up excessively.

high-frequency component. Wire-wound resistors have

the highest inductance, while metal film is somewhat

better. Low-inductance metal-film resistors are also

available. Instead of being spiral-wrapped round a

Bidirectional, High-Side, Current-Sense

Amplifiers with Reference

______________________________________________________________________________________

11

MAX4070

LOAD

TO ADC

2.5V

GSEL

GND

RS-

RS+

REFOUT

OUT

SHDN

2

CELLS

-25mV

25mV

50mV

0

DISCHARGE

CURRENT

CHARGE

CURRENT

-2.5V

5V

2.5V

Figure 2. Bidirectional Current Monitor